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The Benefits of a Liquid-Electron Ionization Liquid Chromatography–Mass Spectrometry InterfaceThis is the fourth in a series of articles exploring current topics in separation science that will be addressed at the HPLC 2019 conference in Milan, Italy, from 16–20 June.
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Enhancing Phosphotyrosine Proteome Coverage Using a Combined ETD and CID Approach on a LTQ Orbitrap XL ETDCollision-induced dissociation (CID) and electron transfer dissociation (ETD) are complementary mass spectrometric fragmentation techniques. We have used CID and ETD in different approaches to analyse tyrosine phosphorylation using a Thermo Scientific LTQ Orbitrap XL equipped with ETD.
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How To Buy Gas Calibration MixesIn January 2004, LCGC Europe published an article on methods for selecting pure gases for analytical applications. 1 Here, the authors expand on this topic by addressing questions regarding gas mixtures - defined simply as more than one gas in a cylinder.
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Rapid Analysis of Pesticides in Difficult Matrices Using GC–MS–MSPesticides are widely used in agriculture to protect crops and to improve efficiency of production. Consequently, governments, food producers and food retailers have a duty to ensure that any residues occurring in foods for human consumption are at or below statutory maximum residue levels (MRLs). Regulation EC 396/2005 adopted in the European Union sets MRLs for more than 500 different pesticides in over 300 different food commodities.
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GCxGC-FID for Qualitative and Quantitative Analysis of PerfumesExploring the use of GCxGC-FID as a technique for qualitative and quantitative analysis of perfumes
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Separation of Quaternary Ammonium Compounds Using a Bonded Polymeric Zwitterionic Stationary PhaseUsing a bonded polymeric zwitterionic stationary phase, in HILIC mode, polar quaternary herbicides like Diquat can easily be retained, with good peak symmetry. The impact of ionic strength and organic content in the mobile phase is discussed.
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Real-Time Profiling of Volatile Malt Aldehydes Using Selected Ion Flow Tube Mass SpectrometryThe authors use headspace SIFT-MS to target and identify volatiles in various malt aldehydes. The specificity and speed are compared to current methodology.
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Fast Analysis of Naproxen Sodium with the Acclaim Trinity P1 Column and Charged Aerosol DetectionESA - a Dionex Company Application Note
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Certificates for Chromatography Standards: Sense and NonsenseThere is more to using and interpreting certificates for chromatography standards than meets the eye
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Method Selection for Trace Analysis of Genotoxic Impurities in PharmaceuticalsThis article describes methods to quantitatively analyse genotoxic and potentially genotoxic impurities in pharmaceutical ingredients
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Generating Make-Up Gas for GC with an In-House Nitrogen GeneratorSince the gas flow required for the separation step in gas chromatography is frequently lower than that required to optimize the detection, nitrogen is used as a make-up gas to increase the gas flow for detection.
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Simultaneous Headspace-GC–FID Analysis for Methanol and Ethanol in Blood, Saliva and Urine: Validation of Method and Comparison of SpecimensA simultaneous headspace-GC–FID method was validated to establish methanol and ethanol assessment in blood, urine and saliva.
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Simultaneous Determination of Formononetin, Biochanin A, Daidzen and Genistein in Trifolium pratense (Red Clover) by HPLCA simple rapid HPLC method for simultaneously determiing formononetin, biochanin A, daidzen and genistein in Red Clover
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Investigating Solvent Purity Using Comprehensive Gas Chromatography: A Study of AcetonesInvestigating Solvent Purity Using Comprehensive Gas Chromatography: A Study of Acetones
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Single Calibrant Approach for the Analysis of Unknowns Using Dual Gradient Pump and Charged Aerosol DetectionQuantification of substances, such as drug impurities or library compounds when pure standards are not available is difficult yet often necessary.
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Continuous Chromatographic Separation of Salt From Sugars by Simulated Moving Bed Technology (SMB) Using Orochem Zucchero ColumnsSimulated Moving Bed technology (SMB) is a continuous chromatography technique widely used in the pharmaceutical/biotechnology industry. The continuous chromatographic separation of sodium sulphate (Na2 SO4) from a mixture of glucose and mannose was established by using the Orochem Zuccheroâ„¢ columns and the SMB technology. The main advantages of SMB over batch chromatography includes better yields, higher purity, and decreased solvent usage, which together make the SMB technology economically viable and ideal for desalting applications.
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*** TEST *** Estimation of the Main Sources of Uncertainty in Chromatographic Analysis: Determination of Biogenic Amines ***TEST ***This article establishes the estimation of the uncertainty associated with the chromatographic determination of biogenic amines. The authors identify and estimate each source of uncertainty to establish the accuracy of results and to obtain a better understanding of the method. Thus, measurement uncertainty was split into two sections: uncertainty related to the working conditions, which considers the equipment used, and inherent uncertainty, which includes the chemical stages indicated in the procedure as well as calibration sources, taking into account the existence of the matrix effect. Recovery studies also were made to quantify the contribution of bias to the overall uncertainty. This parameter was calculated for the determination of biogenic amines in different types of samples.
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Rapid Determination of DNPH Derivatized Carbonyl Compounds by UHPLCCarbonyl compounds, in particular aldehydes, are reactive volatile substances. They are of concern to the public, because they are emitted as air pollutants by a large range of industrial processes and other combustion sources.
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Enhancing Phosphotyrosine Proteome Coverage Using a Combined ETD and CID Approach on a LTQ Orbitrap XL ETDCollision-induced dissociation (CID) and electron transfer dissociation (ETD) are complementary mass spectrometric fragmentation techniques. We have used CID and ETD in different approaches to analyse tyrosine phosphorylation using a Thermo Scientific LTQ Orbitrap XL equipped with ETD.
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Maximizing the Peak Production Rate in Off-line Comprehensive Two-Dimensional Liquid Chromatography with MS DetectionAn optimization strategy to obtain the best possible performance in the shortest analysis time for comprehensive off-line 2D-LC.
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Toward a Universal Detector for Small Molecule Applications: Direct-EI in LC–MSThis article describes the operating principles of the direct-electron ionization (EI) interface, which is becoming more popular in many LC–MS applications. Matrix effects and the role of direct-EI as a universal detector for small molecule analysis are also discussed in detail. The advantages and drawbacks of this approach are described and a comparison with atmospheric pressure ionization (API) interfaces is made. The potential of direct-EI is illustrated with a selection of practical applications.
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A Modular Approach to Pressurized Liquid Extraction with In-Cell CleanupA modification of the popular PLE technique is discussed.
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Method Development for Fast Separation of Polycyclic Aromatic Hydrocarbons Using Micro-LC - The Importance of the Dwell VolumeThis article will shed some light on recent developments of micro-LC and the possibility of applying fast separations while reducing toxic and costly solvent waste.
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Matrix Elimination — In-line Removal of Chloride using InGuard Ag and Na CartridgesIn ion chromatography, the presence of a large amount of matrix ions makes quantification of the target ions difficult. Selective removal of matrix ions - matrix elimination - can be performed by treating a sample with a solid-phase extractant. Halides can be removed by precipitation with silver, which is present as a counterion in a cation-exchange resin. A subsequent treatment with a cation-trapping column removes residual dissolved silver ions.
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Analytical Method Lifecyle of SFC Methods from Development Use to Routine QC Implementation: Supporting Small Molecule R&D and CommercializationIn this article, we review some key considerations for chromatographic technique selection and method development across the full drug process—from early-stage active pharmaceutical ingredient (API) synthesis to routine commercial release activities.
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Simultaneous Determination of Formononentin, Biochanin A, Daidzen and Genistein in Trifolium pratense (Red Clover) by HPLCA simple and rapid HPLC method was established to simultaneously determine the active ingredients of red clover.
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Analytical Techniques in Exploring the Persistent Global PFAS ProblemThe presence of PFAS in the environment requires governmental agencies to establish regulatory limits for PFAS in human essentials, such as drinking water. LC–MS/MS can be used to analyze a wide range of sample types containing PFAS, but avoiding PFAS contamination is critical for this technique to work effectively.
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The Unique Selectivity of π-Interactions for Solid-Phase ExtractionHypercrosslinked polystyrene-type (solid-phase extraction) SPE materials exhibit a unique ability to enter p-interactions with aromatic, heterocyclic and unsaturated compounds. This property permits selective extraction and pre-concentration of the above classes of species from non-polar media and fatty matrices. The principle has been exploited for developing analytical protocols to determine polar furan derivatives in mineral transformer oil, polyaromatic hydrocarbons (PAHs) in smoked fish and for the fractionation of polychlorinated aromatic compounds in environmental matrices.
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Bioanalysis Using Dried Blood Spots: The Biggest Advancement in Bioanalysis Since LC–MS-MS?A discussion on the analytical challenges that both liquid chromatography and mass spectrometry face as well as some potential solutions to these issues.
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Advances in TOF-MS-Based Screening for Food Safety Residue Analysis with a Positive ApproachMass spectrometry plays an increasingly significant role in the analysis of residues and contaminants in food. Here we will illustrate how the combination of ultrahigh-pressure liquid chromatography (UHPLC) and high-resolution time-of-flight-mass spectrometry (TOF-MS) is used to generate a screen of veterinary drug residues in products of animal origin. The use of UHPLC–TOF-MS and dedicated, workflow directed software allows rapid screening for large numbers of residues and automated quantification of positive samples. In addition, we illustrate how the data generated using MSE acquisition mode enable critical structural information to be collected, which offers additional selectivity and confirmatory data for compound identification and facilitates elucidation of the structure of newly discovered compounds.
